textproduct: Quad Cities

KEY MESSAGES

- Isolated to scattered storms can be expected through Sunday. Heavy rain, lightning and gusty winds are the primary risks.

- Humid conditions will continue through much of the coming week. There will be dry periods the first half of next week with mainly isolated to scattered (20-50%) coverage of storms the second half of next week.

- Rises are occurring on area rivers. Refer to the hydro section for more information.

SHORT TERM /THROUGH SUNDAY/

Issued at 220 PM CDT Sat Jul 4 2026

A convectively induced upper level disturbance has developed new convection mainly east of the Mississippi. This convection will grow upscale as it moves further east through the afternoon and evening. Some of the stronger storms will be capable of damaging winds and possibly hail.

West of the Mississippi downward motion has temporarily suppressed any diurnal convection but as daytime heating continues, diurnal convection with a 10-25% coverage will develop through sunset.

The atmosphere has slightly less than 2 inches of water in it but any storm that develops will be capable of producing heavy rainfall and high rainfall rates.

With the risk of heavy rain and that various areas have seen heavy rainfall over the past 48 hours, the flood watch was extended into the evening hours and also expanded into the I-88 and I-80 corridors of Illinois.

Once sunset occurs, most convection will dissipate. However, the models continue to show negative theta e lapse rates through the night. Thus isolated showers or even a thunderstorm are possible through sunrise Sunday.

On Sunday isolated showers and some thunderstorms will be possible through the day as theta e lapse rates remain negative. The key message is that while there is a risk of storms, there will be many hours of dry weather. Additionally, progged profiles indicate the overall atmospheric moisture levels will continue to trend downward thus lowering the overall risk of locally heavy rainfall.

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/

Issued at 220 PM CDT Sat Jul 4 2026

Sunday night through Wednesday Assessment..high (>80%) confidence of humid conditions continuing

The models show northwest flow developing across the CONUS which will bring temperatures down to near normal for the first half of July. The humid conditions will continue but not to the excessive conditions of last week.

There will be weak disturbances moving through the flow aloft through Wednesday. While the model consensus has dry conditions, a rogue diurnal shower or storm during peak heating each day cannot be ruled out.

Wednesday night through Saturday Assessment...high (>80%) confidence of continued humid conditions. Low (15-25%) confidence regarding rain chances.

The humid conditions will continue the second half of the week with a potential uptick in the humidity Wednesday night into Thursday. The various model solutions have a system passing to the north of the area that will push a cool front through the area. While there are some timing differences, late Wednesday night into Thursday evening looks to be the most likely time any rain would be seen.

Not all areas will see rain but overall coverage on the rain looks to be 30-50 percent.

Beyond Thursday evening, the model consensus has a daily risk of rain driven by the diurnal cycle. However, overall coverage will be low at 15-25 percent.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1224 PM CDT Sat Jul 4 2026

Convectively induced vort max will initiate SHRA/TSRA along and east of the Mississippi this afternoon/evening. Overall environment suggests a low probability of a TAF site being impacted. However, a prob30 was included for all TAF sites this afternoon and into the evening. CAMs are struggling to handle the weak forcing but appear to be keying in on areas east of the Mississippi as the primary focus for storms. After 03z/05 isolated SHRA/TSRA will be possible through the night and into Sunday morning.

HYDROLOGY

Issued at 220 PM CDT Sat Jul 4 2026

Rounds of heavy rainfall the past 60 hours and additional heavy rain across Minnesota and Wisconsin are causing area rivers to rise over the next two weeks. Most rivers will experience within bank rises. However, parts of some rivers are forecast to go into flood.

The Wapsipinicon River from Anamosa down to the mouth is forecast to go into flood. Minor flooding is expected near Anamosa with moderate to potentially major flooding near De Witt.

The Iowa River at Marengo is expected to go into minor flood. A flood watch is in effect for the Cedar River near Conesville which may go into flood next week.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Flood Watch until 10 PM CDT this evening for IAZ040>042- 051>054-063>068-076>078-087>089. IL...Flood Watch until 10 PM CDT this evening for ILZ009-015>018- 024. MO...None.